Method of manufacturing a load beam to adjust droop angle

ABSTRACT

A load beam having a bent rail, a suspension that includes the load beam, and a related method for manufacturing a load beam. The method includes providing the load beam before the bent rail is formed, and coining the load beam at a location where the bend will occur in the rail.

FIELD OF THE INVENTION

The invention relates generally to the field of disk drive suspensions.More specifically, the invention relates to coined load beams that areconfigured to be included in disk drive suspensions and a related methodof manufacture.

BACKGROUND

Suspensions for suspending sliders in hard disk drives are well known inthe art. Referring to FIG. 1, in a typical hard disk drive, the drive'sread/write head 10 is included in, or mounted to, a slider 12, which hasan aerodynamic design and is supported by a suspension 14. The slider'saerodynamic design allows for airflow between the slider and the diskdrive's spinning disk 16. This airflow generates lift, which allows theread/write head to fly above the spinning disk's surface an optimaldistance for reading data from, or writing data to, the disk. A typicalsuspension includes a flexure (not shown), a load beam 20, and abaseplate 22. The slider is bonded to the flexure, also referred to as agimbal, which permits the slider to pitch and roll as it tracksfluctuations in the surface 24 of the disk.

The flexure (not shown) is coupled to a distal end 26 of the load beam20, which typically is formed from a flat sheet metal, e.g., stainlesssteel foil, and includes a spring portion 28 that applies a loadingforce, also known as a “pre-load” or “gram force,” to the slider 12. Thepre-load force counteracts the lift that is generated by the interactionbetween the slider and the spinning disk 16, and brings the slider intoa predetermined close spacing to the disk surface 24 while the disk isspinning. The desired pre-load force is achieved by forming one or morebends 30 in the spring portion of the load beam, taking into account thespring constant of the load beam's material, its mass, and the expectedload. A proximal end 32 of the load beam is coupled to the baseplate 22,which is configured to couple to an actuator arm 34. The actuator armmoves under motor control to precisely position the slider, and thus,the drive's read/write head 10 relative to the disk surface.

Referring additionally to the views of an example load beam 20 shown inFIGS. 2A-C, the load beam's distal end 26 is generally a rigid structurehaving its edge regions 36 formed into rails 38 to increase itsrigidity. As shown in FIG. 2A, the load beam has a generally triangularshape 40 that is referred to as a double-delta configuration, whichincludes a first trapezoidal region 42 that is coupled to a secondtrapezoidal region 44. The rails run the length of both sides 46 of theload beam's first and second trapezoidal regions, and the rails are bentat the points 48 where the first and second trapezoidal regions meet.

During manufacturing, the load beam 20 is cut or etched from a flatsheet of metal forming the example shape 50 shown in FIG. 2B. After theoutline of the load beam is cut from the flat sheet of metal, the rails38 are formed by folding up the edge regions 36 on both sides 46 of theload beam. For reference, fold lines 52 are shown in FIG. 2B. Typically,both of the rails are folded in the same direction perpendicular to therest of the load beam, i.e., the first and second trapezoidal regions 42and 44, respectively.

In the case of a double-delta configured load beam 20 having continuousunbroken rails 38 across the intersection of the first and secondtrapezoidal regions 42 and 44, respectively, the load beam can have adrooped shape 54 after the rails are formed, i.e., folded. Referringadditionally to FIG. 2C, the droop, also referred to as unwanted sag,results from the bend 56 at point 48 in each of the rails and can bequantified as the angle θ formed between the plane 58 in which the firsttrapezoidal region lies, i.e., the first plane, and the plane 60 inwhich the second trapezoidal region lies, i.e., the second plane. Thisdroop naturally results when the rails are folded because of the limitedlength of material that makes up the load beam's edge regions 36.

Preferably, a load beam's distal end 26 is a generally planar structurewithout droop 54. Because of manufacturing variability, the droop, i.e.,the angle θ between the first plane 58 and the second plane 60, fordouble-delta configured load beams 20 can vary. This variation in droopcan result in a corresponding variation in the pre-load for the slider12, which, in turn, affects the disk drive's read/write performance.When a load beam has a double-delta configuration, droop can be reducedby breaking the continuum of the rails 38 by forming a gap (not shown)in each of the rails where the first and second trapezoidal regions 42and 44, respectively, meet. However, adding this gap lessens therigidity of the load beam, causing the load beam to offer lessresistance to bending than if the rail was continuous. Alternatively,after the rails are formed, the load beam could be subjected to asecondary bending operation that would reverse the droop, that is,overbend the load beam in a direction opposite to the direction of thedroop to correct the overall shape of the load beam back into agenerally planar shape. However, this secondary bending operation canadd additional variability to the value of the load beam's pre-load.

It should, therefore, be appreciated that there is a need for anefficient method for forming a relatively planar double-deltaconfiguration load beam 20 having rails 38 without having to form a gapin each of the rails before bending the rails into position, and withouthaving to reverse bend the load beam to reverse any droop 54 in the loadbeam. The present invention satisfies these needs.

SUMMARY

Embodiments of the present invention include a coined load beam, asuspension that includes the coined load beam, and a related method formanufacturing the coined load beam. A exemplary method according to theinvention is a method for manufacturing a load beam having a bent rail.The method includes providing the load beam before the bent rail isformed, and coining the load beam at a location where the bend willoccur in the rail.

In other, more detailed features of the invention, the method furtherincludes providing a punch and using the punch to coin the load beam.Also, the method can further include providing a station to which thepunch is coupled, and using the station to move the punch so the punchcoins the load beam. In addition, the rail can have an edge, the railcan have a length along the rail's edge, the punch can be configured toform an indentation in the load beam, and the indentation in the loadbeam can increase the length of the rail's edge.

In other, more detailed features of the invention, the load beam has adouble-delta configuration that includes a first region that lies in afirst plane, and a second region that is coupled to the first region andlies in a second plane. The indentation increase the length of therail's edge so, when the bent rail is formed, the position of the firstplane relative to the second plane is different than it would have beenwithout the indentation. Also, the load beam can include an edge regionand the method can further include forming the bent rail by folding theedge region of the load beam so the edge region no longer lies withinthe first plane or the second plane.

In other, more detailed features of the invention, the first plane isapproximately coplanar to the second plane after the bent rail isformed. Also, the first plane can be at an angle to the second planeafter the bent rail is formed, the punch can include a tip having ashape, and the angle between the first plane and the second plane can bedetermined depending upon the shape of the punch's tip.

An exemplary embodiment of the invention is a load beam that includes anedge region and a bent rail that was formed by folding the edge regionof the load beam. The edge region of the load beam was coined before theedge region was folded into the bent rail.

In other, more detailed features of the invention, the edge region wascoined at a location where the bend was to occur in the rail. Also, theedge region includes an edge, the edge has a length, and the edge regionof the load beam was coined to increase the length of the edge beforethe edge region was folded into the bent rail.

In other, more detailed features of the invention, the load beam wascoined using a punch that included a tip having a shape. The load beamhas a double-delta configuration which includes a first region that liesin a first plane and a second region that is coupled to the first regionand lies in a second plane. The first plane has an orientation relativeto the second plane such that the first plane is approximately coplanarto the second plane, or the first plane and the second plane form anangle having a value that is affected by the shape of the tip.

Another exemplary embodiment of the invention is a suspension that isconfigured to be used in a disk drive. The suspension includes a loadbeam having an edge region, and a bent rail that was formed by foldingthe edge region of the load beam. The edge region of the load beam wascoined before the edge region was folded into the bent rail.

In other, more detailed features of the invention, the load beam iscoined using a punch that includes a tip having a shape that isconfigured to form an indentation in the load beam's edge region. Theload beam has a double-delta configuration which includes a first regionthat lies in a first plane, and a second region that is coupled to thefirst region and lies in a second plane. The first plane and the secondplane form an angle, and the value of the angle between the first andsecond planes is affected by the shape of the punch tip.

Another exemplary embodiment of the invention is a punch that isconfigured to coin a disk drive suspension load beam having an edgeregion that includes an edge and is formed into a bent rail. The punchincludes a tip that is configured to press into the load beam and toform an indentation in the edge region of the load beam before the edgeregion is formed into the bent rail. The indentation in the load beamlengthens the edge.

In other, more detailed features of the invention, the punch is made oftungsten carbide, tool steel, heat-treated steel, or ceramic. The punchcan be coated with titanium nitride or diamond-like carbon. Also, thetip can have a first shape along a first axis that is a square shape, arectangular shape, a step shape, a triangular shape, an offsettriangular shape, a semicircular shape, an offset semicircular shape, anarched shape, an offset arched shape, a peaked shape, an offset peakedshape, or a combination thereof. In addition, the tip can have a secondshape along a second axis that is a square shape, a rectangular shape, astep shape, a triangular shape, an offset triangular shape, asemicircular shape, an offset semicircular shape, an arched shape, anoffset arched shape, a peaked shape, an offset peaked shape, or acombination thereof. Furthermore, the tip can have a third shape along athird axis that is selected from the group consisting of a square shape,a rectangular shape, a step shape, a triangular shape, a trapezoidalshape, an offset triangular shape, a diamond shape, a circular shape, anelliptical shape, a semicircular shape, an offset semicircular shape, anarched shape, an offset arched shape, a peaked shape, an offset peakedshape, or a combination thereof.

In other, more detailed features of the invention, the tip can have aheight along a first axis that ranges from approximately 0.0050 inch toapproximately 0.0051 inch; a width along a second axis that ranges fromapproximately 0.010 inch to approximately 0.050 inch; and a length alonga third axis that ranges from approximately 0.010 inch to approximately0.050 inch. Also, the punch can further include a stop that isconfigured to limit a depth of the indentation that is formed in theedge region of the load beam by the tip.

Other features of the invention should become apparent to those skilledin the art from the following description of the preferred embodimentstaken in conjunction with the accompanying drawings, which illustrate,by way of example, the principles of the invention, the invention notbeing limited to any particular preferred embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood with reference to the followingdescription, equations, appended claims, and accompanying drawings,where:

FIG. 1 is a perspective view of an example disk drive suspension andslider.

FIG. 2A is a perspective view of an example load beam having adouble-delta configuration.

FIG. 2B is a top plan view of the example load beam shown in FIG. 2Abefore the load beam's rails are folded.

FIG. 2C is a side elevational view of the example load beam shown inFIG. 2A.

FIG. 3A is a perspective view of an example station that is configuredto coin a load beam according to a preferred embodiment. The examplestation includes a pair of punches, a cover plate, and a base.

FIG. 3B is a perspective view of an example base according to apreferred embodiment.

FIG. 3C is a perspective view of an example cover plate according to apreferred embodiment.

FIG. 3D is a partial perspective view of an example punch according to apreferred embodiment.

FIG. 4 is a partial top plan view of an example cover plate that isincluded in the station shown in FIG. 3A.

FIG. 5A is a partial sectional side view of a load beam and the punch,the cover plate, and the base included in the station shown in FIG. 3Ashowing the punch moving downward toward the load beam.

FIG. 5B is another partial sectional side view of the load beam, thepunch, the cover plate, and the base included in the station shown inFIG. 3A with the punch pressed against the load beam.

FIG. 5C is another partial sectional side view of the load beam, thepunch, the cover plate, and the base included in the station shown inFIG. 3A with the punch moving upward and away from the load beam.

FIG. 5D is a partial sectional side view of a distal end of the loadbeam, the punch, the cover plate, and the base included in FIG. 5B withthe punch pressed against the load beam showing the punch's stop incontact with the base.

FIG. 6A is a partial perspective view the punch shown in FIGS. 5A-D.

FIG. 6B is a partial side elevational view of a distal end of the loadbeam shown in FIG. 6A as seen along a first axis.

FIG. 6C is a partial side elevational view of the distal end of the loadbeam shown in FIG. 6A as seen along a second axis.

FIG. 6D is a partial plan view of the distal end of the load beam shownin FIG. 6A as seen along a third axis.

FIG. 7A is a partial side elevational view of a tip at a distal end of aload beam having a square shape along the first axis according to apreferred embodiment.

FIG. 7B includes partial side elevational views of tips at distal endsof load beams having rectangular shapes along the first axis accordingto preferred embodiments.

FIG. 7C includes partial side elevational views of tips at distal endsof load beams having step shapes along the first axis according topreferred embodiments.

FIG. 7D is a partial side elevational view of a tip at a distal end of aload beam having a triangular shape along the first axis according to apreferred embodiment.

FIG. 7E is a partial side elevational view of a tip at a distal end of aload beam having an offset rectangular shape along the first axisaccording to a preferred embodiment.

FIG. 7F is a partial side elevational view of a tip at a distal end of aload beam having a semicircular shape along the first axis according toa preferred embodiment.

FIG. 7G is a partial side elevational view of a tip at a distal end of aload beam having an offset semicircular shape along the first axisaccording to a preferred embodiment.

FIG. 7H is a partial side elevational view of a tip at a distal end of aload beam having an arched shape along the first axis according to apreferred embodiment.

FIG. 7I is a partial side elevational view of a tip at a distal end of aload beam having an extended arched shape along the first axis accordingto a preferred embodiment.

FIG. 7J is a partial side elevational view of a tip at a distal end of aload beam having a peaked shape along the first axis according to apreferred embodiment.

FIG. 7K is a partial side elevational view of a tip at a distal end of aload beam having an offset peaked shape along a first axis according toa preferred embodiment.

FIG. 8A is a partial side elevational view of a tip at a distal end of aload beam having a square shape along the second axis according to apreferred embodiment.

FIG. 8B includes partial side elevational views of tips at distal endsof load beams having rectangular shapes along the second axis accordingto preferred embodiments.

FIG. 8C includes partial side elevational views of tips at distal endsof load beams having step shapes along the second axis according topreferred embodiments.

FIG. 8D includes partial side elevational views of tips at distal endsof load beams having triangular shapes along the second axis accordingto preferred embodiments.

FIG. 8E includes partial side elevational views of tips at distal endsof load beams having offset triangular shapes along the second axisaccording to preferred embodiments.

FIG. 8F includes partial side elevational views of tips at distal endsof load beams having semicircular shapes along the second axis accordingto preferred embodiments.

FIG. 8G includes partial side elevational views of tips at distal endsof load beams having offset semicircular shapes along the second axisaccording to preferred embodiments.

FIG. 8H includes partial side elevational views of tips at distal endsof load beams having an arched shapes along the second axis according topreferred embodiments.

FIG. 8I includes partial side elevational views of tips at distal endsof load beams having offset arched shapes along the second axisaccording to preferred embodiments.

FIG. 8J includes partial side elevational views of tips at distal endsof load beams having peaked shapes along the second axis according topreferred embodiments.

FIG. 8K includes partial side elevational views of tips at distal endsof load beams having offset peaked shapes along the second axisaccording to preferred embodiments.

FIG. 9A is a partial plan view of a tip at a distal end of a load beamhaving a square shape along the third axis according to a preferredembodiment.

FIG. 9B includes partial plan views of tips at distal ends of load beamshaving rectangular shapes along the third axis according to preferredembodiments.

FIG. 9C includes partial plan views of tips at distal ends of load beamshaving step shapes along the third axis according to preferredembodiments.

FIG. 9D includes partial plan views of tips at distal ends of load beamshaving triangular shapes along the third axis according to preferredembodiments.

FIG. 9E includes partial plan views of tips at distal ends of load beamshaving trapezoidal shapes along the third axis according to preferredembodiments.

FIG. 9F includes partial plan views of tips at distal ends of load beamshaving offset triangular shapes along the third axis according topreferred embodiments.

FIG. 9G is a partial plan view of a tip at a distal end of a load beamhaving a diamond shape along the third axis according to a preferredembodiment.

FIG. 9H is a partial plan view of a tip at a distal end of a load beamhaving a circular shape along the third axis according to a preferredembodiment.

FIG. 9I is a partial plan view of a tip at a distal end of a load beamhaving an elliptical shape along the third axis according to a preferredembodiment.

FIG. 9J includes partial plan views of tips at distal ends of load beamshaving semicircular shapes along the third axis according to preferredembodiments.

FIG. 9K includes partial plan views of tips at distal ends of load beamshaving offset semicircular shapes along the third axis according topreferred embodiments.

FIG. 9L includes partial plan views of tips at distal ends of load beamshaving arched shapes along the third axis according to preferredembodiments.

FIG. 9M includes partial plan views of tips at distal ends of load beamshaving offset arched shapes along the third axis according to preferredembodiments.

FIG. 9N includes partial plan views of tips at distal ends of load beamshaving peaked shapes along the third axis according to preferredembodiments.

FIG. 9O includes partial plan views of tips at distal ends of load beamshaving offset peaked shapes along the third axis according to preferredembodiments.

FIG. 10 is a partial perspective view of a punch having a conicallyshaped tip.

FIG. 11A is a top plan view of an embodiment of a coined load beamaccording to a preferred embodiment.

FIG. 11B is a perspective view of the coined load beam shown in FIG. 11Awith the rails partially folded.

FIG. 11C is a perspective view of the coined load beam shown in FIG. 11Awith the rails folded into their final positions.

FIG. 12A is a side elevational view of an embodiment of a coined loadbeam having a droop angle that is greater than zero according to apreferred embodiment.

FIG. 12B is a side elevational view of another embodiment of a coinedload beam having a droop angle that is approximately zero according to apreferred embodiment.

FIG. 12C is a side elevational view of another embodiment of a coinedload beam having a droop angle that is less than zero according to apreferred embodiment.

FIG. 13 is a flowchart for an example method of manufacturing a coinedload beam according to the invention.

DETAILED DESCRIPTION

The present invention alters the length of the rails 38 in double-deltaconfigured load beams 20 to reduce or eliminate droop 54, or to reducedroop variability. As previously discussed, a load beam that includes adouble-delta configuration includes a first trapezoidal region 42, aka afirst region, which lies in a first plane 58 and is coupled to a secondtrapezoidal region 44, aka a second region, which lies in a second plane60. In embodiments of the invention, the length of the rails areincreased slightly before the rails are folded so the first plane of thefirst trapezoidal region remains approximately coplanar with the secondplane of the second trapezoidal region after the rails are folded. Morespecifically, the metal that makes of the rails is lengthened using acoining process before the rails are folded, e.g., while the load beamis still a flat piece of metal. In other embodiments, the droop, or theangle, between the first plane and the second plane is adjusted to be apredetermined value by coining the rails using a punch having a knowntip shape and size before the rails are folded.

FIG. 3A is an illustration of an example work station 62 where flat loadbeams 20 are coined as part of a manufacturing process according to theinvention after the load beams have been cut from a sheet of metal, andbefore the rails 38 of the load beam are folded. Referring additionallyto FIG. 3B, the station includes a base 64, which has a relatively flattop surface 66 on which the load beam is positioned before coining. Thebase can be made of, for example, tungsten carbide, tool steel, orceramic, and typically has a height “H_(b)” of approximately 0.750 inch,a width “W_(b)” of approximately 1.000 inch, and a length “L_(b)” ofapproximately 1.200 inches.

Referring additionally to FIG. 3C, the station 62 also includes a coverplate 68, which is configured to rest on top of the base 64 and the loadbeam 20, and to hold the load beam in place between the base and thecover plate during the coining process. As shown in FIGS. 3A and 3C, thecover plate is a separate block of material that can be secured intoposition over the base. For example, in the embodiment shown in FIGS. 3Aand 3C, the cover plate includes a pair of securing bores 70 that areconfigured to receive dowels that are coupled to the base by insertingthe dowels into dowel holes 72. In this embodiment, the cover plate canbe secured to the base by initially lining up the cover plate's securingbores with the dowels that extend upward from the base, and dropping thecover plate on top of the base so the dowels insert into the securingbores.

The cover plate 68 can be made of, for example, tungsten carbide, toolsteel, or ceramic, and typically has a height “H_(c)” of approximately0.375 inch, a width “W_(c)” that ranges from approximately 1.178 inchesto approximately 1.182 inches, and a length “L_(c)” that ranges fromapproximately 1.198 inches to approximately 1.202 inches. The coverplate also includes two processing bores 74, each having a generallysquare cross section, which are configured to receive two punches 76(see FIG. 3D) that extend downward from a punch retainer 78, as shown inFIG. 3A. Referring additionally to FIG. 4, which is a partial top planview of a region of the cover plate that includes the processing bores.Edges 80 of the load beam, which is covered by the cover plate, can beseen through the processing bores.

Referring again to FIGS. 3A and 3D, which is a perspective view of anexample punch 76, the punches are secured to a top part 82 of thestation 62 via the punch retainer 78 that is configured to receive thepunches and to couple to the top part. The top part is configured tomove up and down in a vertical manner, and thus, alter the position ofthe punches relative to the load beam 20, the cover plate 68, and thebase 64. The punches can be made of, for example, tungsten carbide, toolsteel, heat-treated steel, or ceramic, and typically have a height“H_(p)” that ranges from approximately 0.1248 inch to approximately0.1250 inch, a width “W_(p)” that ranges from approximately 0.1248 inchto approximately 0.1250 inch, and a length “L_(p)” that ranges fromapproximately 2.055 inches to approximately 2.065 inches. Also, thepunches can be coated with a material, e.g., titanium nitride ordiamond-like carbon (“DLC”), that enhances wear resistance, reduces partgalling, and decreases particulate generation.

During the coining process, the load beam 20, the cover plate 68, andthe punches 76 are aligned so that a distal end 84 of each punch, whenlowered by the top part 82 of the station 62, will contact an edgeregion 36 of the load beam where the first trapezoidal region 42 meetsthe second trapezoidal region 44 of the load beam. In particular, a usercan prompt the station's top part to move downward toward the base 64.As the top part moves downward, both punches move toward the coverplate, and the distal ends of punches eventually insert into the coverplate through the processing bores 74. With continued downward movementof the station's top part, the distal ends of the punches contact theload beam and deform the sheet of material that makes up the load beam.

Referring additionally to the partial cross-sectional side views shownin FIGS. 5A-D, the distal end 84 of one of the punches 76 is shownpushing down through a processing bore 74 in the cover plate 68 (seeFIG. 5A), pressing down into the top surface 86 of the load beam 20 (seeFIG. 5B), which is supported on the base 64, and then lifting away fromthe load beam and upward back through the processing hole (see FIG. 5C).The cover plate holds the load beam in place throughout the coiningprocess and particularly as the punch is drawn upward and away from theload beam. The example punch shown in FIGS. 5A-D includes a rounded,semicircular tip 88, which pushes into the load beam and leaves acorresponding semicircular indentation 90 in the load beam when it liftsback from the top surface of the load beam. After the station's top part82 lifts the punches above the cover plate, the cover plate can belifted off the load beam, and the coined load beam can be lifted off ofthe base and moved from the station 62 to another location, e.g.,another station, where additional processing steps can be performed onthe load beam, e.g., the rails 38 can be folded.

The punch 76 coins the load beam 20 by striking the load beam along itsedge regions 36, and in doing so, pushes the load beam material out andaway from its initial location. As shown in FIG. 5C, the coining processresults in an indentation 90 in the load beam. In example embodiments,the thickness “LB_(t)” of the load beam can range from approximately0.0004 inch to approximately 0.004 inch before coining. After coining,the load beam in the location of the indentation can have a thicknessthat ranges from approximately 0.00005 inch to approximately thethickness “LB_(t)” of the load beam minus 0.00005 inch. Referringadditionally to FIG. 5D, in addition to the tip 88, the distal end 84 ofthe punch includes a stop 92, which is configured to contact the base 64after the tip of the punch impacts the load beam. The dimensions of thestop and the location of the stop on the distal end of the punch areconfigured such that the stop does not touch the load beam during thecoining process, and the stop prevents the tip from pushing through theentire thickness “LB_(t)” of the load beam. Thus, the stop limits thedepth of the indentation that is formed in the edge region of the loadbeam. For example, as shown in the embodiment of FIG. 5D, the height“H_(s)” of the stop matches the thickness of the load beam “LB_(t)”. Inother embodiments, the height of the stop may be greater than the loadbeam's thickness.

Referring additionally to FIGS. 6A-D, a partial perspective view isshown in FIG. 6A of the example punch 76 shown in FIGS. 5A-D with theassociated directional axes, i.e., the x-axis, the y-axis, and z-axis,in agreement with the corresponding axes shown in FIG. 5A. The punch'sdistal end 84 includes a tip 88 that is semicircular when viewed alongthe x-axis (see FIG. 6B) and having a height “H_(t)”, and rectangularwhen viewed along either the y or the z axes (see FIGS. 6C and 6D,respectively). The tip has a length “L_(t)” along the y-axis and a width“W_(t)” along the z-axis. The height “H_(t)”, width “W_(t)”, and length“L_(t)” of a punch tip can vary greatly depending upon the thickness“LB_(t)” of the load beam 20 and the desired dimensions of the resultingindentation 90 in the load beam. For example, the height “H_(t)” of thetip can ranges from approximately the height “H_(s)” of the stop 92minus 0.00005 inch, e.g., approximately 0.0050 inch, to approximatelythe height “H_(s)” of the stop minus the thickness “LB_(t)” of the loadbeam plus 0.00005 inch, e.g., approximately 0.0051 inch, when thethickness “LB_(t)” of the load beam ranges in value from approximately0.0004 inch to approximately 0.004 inch. Also, the width “W_(t)” of thetip typically ranges from approximately 0.010 inch to approximately0.050 inch, and the length “L_(t)” of the tip typically ranges fromapproximately 0.010 inch to approximately 0.050 inch.

While the example punch 76 shown in FIGS. 5A-D and FIGS. 6A-D has arounded semicircular tip 88, the tip of a punch according to embodimentsof the invention can be any of a wide variety of shapes including theexample shapes 94-224 shown in the partial side elevational views ofvarious example tips of FIGS. 7-9. In particular, FIGS. 7A-K showgeneralized example tip shapes 94-118 as viewed along the x-axis (seeFIGS. 5A and 6A for the orientation of the x-axis relative to thepunch). The example shapes illustrated in FIGS. 7A-K include a squareshape 94 (see FIG. 7A), rectangular shapes 96 and 98 (see FIG. 7B), stepshapes 100 and 102 (see FIG. 7C), a triangular shape 104 (see FIG. 7D),an offset triangular shape 106 (see FIG. 7E), a semicircular shape 108(see FIG. 7F) (the shape of the tip shown in FIGS. 5A-D and FIGS.6A-6D), an offset semicircular shape 110 (see FIG. 7G), an arched shape112 (see FIG. 7H), an offset arched shape 114 (see FIG. 7I), a peakedshape 116 (see FIG. 7J), and an offset peaked shape 118 (see FIG. 7K).The punch tip can have other shapes as viewed along the x-axis, forexample, combinations of any of the general shapes shown in FIGS. 7A-K.

Referring additionally to FIGS. 8A-K, the tip 88 along the y-axisdirection can have various shapes. Several example tip shapes 120-176are shown in the partial side elevational views of FIGS. 8A-K, forexample, a square shape 120 (see FIG. 8A), rectangular shapes 122 and124 (see FIG. 8B), step shapes 126 and 128 (see FIG. 8C), triangularshapes 130-134 (see FIG. 8D), offset triangular shapes 136-140 (see FIG.8E), semicircular shapes 142-146 (see FIG. 8F), offset semicircularshapes 148-152 (see FIG. 8G), arched shapes 154-158 (see FIG. 8H),offset arched shapes 160-164 (see FIG. 8I), peaked shapes 166-170 (seeFIG. 8J), and offset peaked shapes 172-176 (see FIG. 8K). The punch tipcan have other shapes as viewed along the y-axis, for example,combinations of any of the general shapes shown in FIGS. 8A-K.

Referring additionally to FIGS. 9A-O, the shape of the tip 88 lookingvertically down on along the z-axis direction can vary greatly. Forexample, the tip, as viewed along the z-axis direction, can have asquare shape 178 (see FIG. 9A), rectangular shapes 180 and 182 (see FIG.9B), step shapes 184 and 186 (see FIG. 9C), triangular shapes 188 and190 (see FIG. 9D), trapezoidal shapes 192 and 194 (see FIG. 9E), offsettriangular shapes 196 and 198 (see FIG. 9F), a diamond shape 200 (seeFIG. 9G), a circular shape 202 (see FIG. 9H), an elliptical shape 204(see FIG. 9I), semicircular shapes 206 and 208 (see FIG. 9J), offsetsemicircular shapes 210 and 212 (see FIG. 9K), arched shapes 214 and 216(see FIG. 9L), offset arched shapes 218 and 220 (see FIG. 9M), peakedshapes 222 and 224 (see FIG. 9N), or offset peaked shapes 226 and 228(see FIG. 9O).

Because the shape of the tip 88 can taper along one or more of the threeaxes, i.e., the x-axis, the y-axis, and the z-axis, embodiments of thetip can make an indentation 90 that is deeper and/or wider at the edge80 (see FIG. 4) of the rail 38. In these embodiments, more pressure isapplied by the tip at the edge of the rail and less at the inside edge230 of the rail adjacent to where the fold is to occur (see the foldline 232). This results in the edge 80 of the rail being lengthened morethan in regions of the rail 230 that are closer to where the rail is tobe folded. An example of a tip having a tapered shape is shown in FIG.10, which is a partial perspective view of a conically shaped tip 234having views along the x, y, and z axes as shown in FIGS. 7F, 8E, and9E, respectively.

Referring additionally to the top plan view shown in FIG. 11A of anexample embodiment of a load beam 20 that has been coined, the extralength that needs to be added to the rail 38 so that the firsttrapezoidal region 42 and the second trapezoidal region 44 are coplanarafter the load beam rails are folded into their final position (see theperspective view of FIG. 11C) can be calculated based on the followingequation:Extra Length=2π*R _(H)*φ/360°

-   -   Where:    -   R_(H) is the rail height as shown in FIG. 11A, and    -   φ is the difference in angle in degrees between the first        trapezoidal region and the second trapezoidal region as shown in        FIG. 11A.        For example, if the height of the rail (“R_(H)”) is 0.0075 inch        and the difference in angle between the first trapezoidal region        and second trapezoidal region is 7.93°, then the extra length        that is added to the rail after coining is 2π*0.0075        inch*7.93°/360°, which equals 0.001 inch.

In FIGS. 11A-C, embodiments of the load beam 20 are shown that alreadyhas been coined using a pair of punches 76 with each punch having a tip88 with a semicircular shape 108 in the x-direction, a rectangular shape124 in the y-direction, and a rectangular shape 182 in the z-direction.FIG. 11A shows the load beam after the load beam was coined and beforethe load beam's rails 38 are folded. FIG. 11B shows the load beam'srails being folded up on both sides. FIG. 11C shows the load beam afterthe rails have been folded completely into their final positions, asbent rails 236.

As previously noted, the load beam rails 38 after coining haveadditional length that aids in maintaining the flatness of the load beam20 after the rail folding process is complete. In addition to using thecoining process to add length to the rails so that the load beam canremain planar after the rails are folded, the coining process can bemodified, for example, by using a punch tip 88 that has a differentshape in one or more of the axial directions. By using a tip having adifferent shape 94-228, or a tip having different dimensions, i.e.,H_(t), W_(t), and/or L_(t), the shape and dimension of the resultingindentation 90 in the load beam can be changed, which, in turn, affectsthe amount and the location of the additional length that is added tothe rail. This change in the rail length affects the angle θ between thefirst plane 58 and the second plane 60 of the double-delta configurationload beam after the rails are folded. In fact, the shape of the tipdictates the amount of increased rail length, and therefore, dictatesthe amount of droop 54 for the coined load beam. Accordingly, bycarefully selecting the shape and dimension of the punch's tip, the loadbeam's droop can be predetermined.

This variability in droop 54 is shown in the side elevational view ofFIGS. 12A-C. FIG. 12A shows an embodiment of a coined load beam 20 wherethe second trapezoidal region 44 is bent upward relative to the firsttrapezoidal region 42, and thus, the angle θ between the first plane 58and the second plane 60 is greater than zero. In another embodimentshown in FIG. 12B, the first trapezoidal region and the secondtrapezoidal region are approximately coplanar, and thus, the angle θbetween the first and second planes is approximately zero. In anadditional embodiment shown in FIG. 12C, the second trapezoidal regionis bent downward from the first trapezoidal region, and thus, the angleθ between the first plane and the second plane is less than zero.

Accordingly, the angular distinction between the first and second planes58 and 60, respectively, can be adjusted and/or designed to be aspecific value using the coining process of invention. Morespecifically, the type of punch tip 88 used to coin the load beam 20helps to determine the final angular position θ of the secondtrapezoidal region 44 relative to the first trapezoidal region 42 afterthe rails 38 are folded into place. By fine tuning the shape 94-228 ofthe tip of the punch, and therefore the amount the rail is lengthened,the angle θ of droop 54 in the load beam can be fine tuned to be aspecific predetermined value, e.g., a value of approximately zero,greater than zero, or less than zero. So, the angle of load beam droopis predictable as a result of the coining process described herein.

An exemplary method for manufacturing a coined load beam according tothe invention is illustrated in the algorithm 238 of FIG. 13. Afterstarting the method at step 240, the next step 242 is to provide a loadbeam 20 before its rails 38 are folded into bent rails 236. Next, atstep 244, a station 62 is provided which includes a punch 76 that isconfigured to coin the load beam. At step 246, the station is used tomove the punch so that the punch coins the load beam and forms anindentation 90 in the load beam at a location 48 where the bend 56 willeventually be formed in the bent rail 236. Next, after the load beam iscoined, the rail 38 is folded into its final position at step 248. Themethod ends at step 250.

Advantageously, the coining process of this invention and its associatedhardware, e.g., the punch 76 and the punch tip 88, eliminate or minimizeunwanted droop 54 in disk drive suspensions 14. Also, by adjusting theshape 94-228 and/or dimensions, i.e., H_(t), W_(t), and/or L_(t), of thepunch tip, the amount of length that is added to the coined rails 38,and thus, the amount of droop can be selected to be a particular value.So, the amount of droop in load beams manufactured according to theinvention is infinitely variable.

All features disclosed in the specification, including the claims,abstract, and drawings, and all the steps in any method or processdisclosed, may be combined in any combination, except combinations whereat least some of such features and/or steps are mutually exclusive. Eachfeature disclosed in the specification, including the claims, abstract,and drawings, can be replaced by alternative features serving the same,equivalent, or similar purpose, unless expressly stated otherwise. Thus,unless expressly stated otherwise, each feature disclosed is one exampleonly of a generic series of equivalent or similar features.

The foregoing detailed description of the present invention is providedfor purposes of illustration, and it is not intended to be exhaustive orto limit the invention to the particular embodiments disclosed. Theembodiments may provide different capabilities and benefits, dependingon the configuration used to implement the key features of theinvention. Accordingly, the scope of the invention is defined only bythe following claims.

1. A method for manufacturing a load beam having a rail having a bendtherein, the load beam further having an edge region, the methodcomprising: a. before the edge region of the load beam is bent to formthe bent rail, coining the load beam at a location where the bend willoccur in the rail, said coining being performed by pressing a punch intothe load beam, the punch comprising a tip that is configured to pressinto the load beam and to form an indentation in the edge region of theload beam, the indentation in the load beam lengthening the edge region;and b. bending the rail to form said bend therein.
 2. The methodaccording to claim 1, wherein the punch is made of a material that isselected from the group consisting of tungsten carbide, tool steel,heat-treated steel, and ceramic.
 3. The method according to claim 1,wherein the punch is coated with a material that is selected from thegroup consisting of titanium nitride and diamond-like carbon.
 4. Themethod according to claim 1, wherein: the tip has a first shape along afirst axis that is selected from the group consisting of a square shape,a rectangular shape, a step shape, a triangular shape, an offsettriangular shape, a semicircular shape, an offset semicircular shape, anarched shape, an offset arched shape, a peaked shape, an offset peakedshape, and a combination thereof.
 5. The method according to claim 4,wherein: the tip has a second shape along a second axis that is selectedfrom the group consisting of a square shape, a rectangular shape, a stepshape, a triangular shape, an offset triangular shape, a semicircularshape, an offset semicircular shape, an arched shape, an offset archedshape, a peaked shape, an offset peaked shape, and a combinationthereof.
 6. The method according to claim 5, wherein: the tip has athird shape along a third axis that is selected from the groupconsisting of a square shape, a rectangular shape, a step shape, atriangular shape, a trapezoidal shape, an offset triangular shape, adiamond shape, a circular shape, and elliptical shape, a semicircularshape, an offset semicircular shape, an arched shape, an offset archedshape, a peaked shape, an offset peaked shape, and a combinationthereof.
 7. The method according to claim 1, wherein: a. the tip has aheight along a first axis; b. the tip has a width along a second axisthat ranges from approximately 0.010 inch to approximately 0.050 inch;and c. the tip has a width along a third axis that ranges fromapproximately 0.010 inch to approximately 0.050 inch.
 8. The methodaccording to claim 1 wherein the punch further comprises a stop that isconfigured to limit a depth of the indentation that is formed in theedge region of the load beam by the tip.
 9. The method of claim 1wherein: the load beam has a double-delta configuration, thedouble-delta configuration including a first region that lies in a firstplane and a second region that lies in a second plane; and the firstplane is approximately coplanar to the second plane after the rail isbent, the position of the first plane relative to the second plane beingdifferent than it would have been without the indentation.
 10. Themethod of claim 1 wherein the indentation is coined into the load beamat a location that is adjacent to both the first region and the secondregion.
 11. The method of claim 1 wherein the indentation is at alocation where the first region meets the second region.
 12. A methodfor manufacturing a load beam having a double-delta configuration, thedouble-delta configuration including a first region that lies in a firstplane and a second region that lies in a second plane, the load beamfurther having a rail, the rail having a bend therein and also having arail edge, the method comprising: a. using a punch to coin the load beamto form an indentation therein at a location where the bend in the railedge will occur, the indentation increasing a length of the rail edge;b. then bending the rail and; c. wherein the first plane isapproximately coplanar to the second plane after the rail is bent, andthe position of the first plane relative to the second plane isdifferent than it would have been without the indentation.
 13. A methodfor manufacturing a load beam, comprising: securing a flat piece ofmetal so that the flat piece of metal can be worked, the flat piece ofmetal including two differently shaped regions thereof; lengtheningopposite edges of the flat piece of metal by working the metal within anarea where the two differently shaped regions meet; after the metal hasbeen worked to lengthen the opposite edges, then bending the edges toform stiffening edge rails of the load beam; and coupling the load beamto a means for coupling the load beam to an actuator arm.
 14. The methodof claim 13 wherein the lengthening of the opposite edges by working themetal comprises pressing one or more punches into the piece of flatmetal at two different locations to create two respective indentationsinto the metal on opposite lateral sides thereof, the indentations beingdisposed between the two differently shaped regions of the flat metal.15. The method of claim 14 wherein, after the lengthening and bendingsteps, the stiffening edge rails each include respective ones of the twoindentations.
 16. The method of claim 13 wherein the two differentlyshaped regions are each trapezoidal.
 17. The method of claim 13 whereinafter said bending, the two differently shaped regions are generallycoplanar, but would not have been coplanar without the indentations havebeen formed in the load beam.